Lance Armstrong waltzed in to the 2012 Vanity Fair Oscar party in Hollywood on Feb. 26. / Jordan Strauss, Invision/AP

by Brent Schrotenboer, USA TODAY Sports

by Brent Schrotenboer, USA TODAY Sports

Lance Armstrong plans to cooperate with anti-doping officials to help clean up the sport of cycling but still has issues with U.S. Anti-Doping Agency chief Travis Tygart, Armstrong attorney Tim Herman wrote in a letter sent Friday.

Tygart recently taped an interview with "60 Minutes" in which he accused Armstrong of lying during his televised confession last week with talk-show host Opray Winfrey. The "60 Minutes" interview is scheduled to air Sunday on CBS.

"Lance's commitment to the truth and reconciliation process is firm, despite the attempt at piling on through more appearances by Mr. Tygart on '60 Minutes,'" Herman wrote in a letter addressed to USADA attorney Bill Bock.

USADA set a deadline of Feb. 6 for Armstrong to cooperate in exchange for a possible reduction of his lifetime ban from sanctioned sports. Herman said Armstrong was willing to cooperate with USADA but could not meet that deadline because of prior obligations. Instead, Herman said Armstrong plans to work with a Truth and Reconciliation Commission being established by two other governing bodies: the World Anti-Doping Agency and the International Cycling Union (UCI).

"Lance will cooperate fully in a true effort to 'clean up cycling,'" Herman wrote Bock in the letter obtained Friday by USA TODAY Sports.

Because pro cycling is largely a European sport and USADA doesn't have the authority to be involved with the other 95 percent of cycling competitors, WADA and UCI are better positioned for the task than USADA, Herman wrote.

"We have been asked to and intend to participate in this commission and would like to coordinate things such as your (USADA's) interview request with all pertinent bodies in this process," Herman said. "That cannot happen in the next two weeks."

In the interview with Winfrey, Armstrong confessed to cheating during his cycling career and lying about it for more than a decade. He said he used banned drugs or blood transfusions to gain in edge in all seven of his victories in the Tour de France from 1999 to 2005.

USADA and the WADA want Armstrong to make a full confession under oath before a lessening of his lifetime ban can even be considered. If he cooperates and provides further assistance to help clean up doping in cycling, his ban could be shortened to eight years, according to the WADA code. USADA previously met with Armstrong in December, a meeting that did not go well.

"Mr. Armstrong has already been provided well over a month since our meeting in December to consider whether he is going to be part of our ongoing efforts to clean up the sport of cycling," Tygart said in a statement Friday. "He has been given a deadline of February 6th to determine whether he plans to come in and be part of the solution. Either way, USADA is moving forward with our investigation on behalf of clean athletes."

Herman expressed displeasure in Tygart's remarks airing on "60 Minutes." In that interview, Tygart said Armstrong lied to Winfrey when he said he never doped during his comeback to cycling in 2009 and 2010.

Tygart told "60 Minutes" that Armstrong's blood tests from 2009 and 2010 show that there was a "one to a million chance that it was due to something other than doping."

Tygart also suggested there was a big reason for Armstrong to lie about this: Under the statute of limitations for criminal fraud, he would still be subject to prosecution.

"I note with disappointment yet another appearance by Mr. Tygart on '60 Minutes' being advertised heavily for this weekend," Herman wrote. "The press releases tout it as more criticism of and attacks on Lance, despite no shortage of that following his recent revelations."

Herman said other riders had denied doping but only came forward to clean up cycling when faced with criminal charges and a grant of amnesty.

"Although USADA has never dealt with Lance on a similar basis, we have committed to cooperate with a truth and reconciliation process that truly can 'clean up cycling,'" Herman wrote.

USADA released a massive evidence file in October that detailed Armstrong's doping. Before then, Armstrong denied it and accused USADA of conducting a witch hunt against him. In his interview with Winfrey, he still said many of USADA's allegations against him were not true.

For example, Tygart previously told "60 Minutes Sports" that one of Armstrong's representatives once offered USADA a donation of about $250,000 â?? an offer USADA considered improper.

Armstrong said it wasn't true in his interview with Winfrey.

In the new "60 Minutes" interview, Tygart said he took the call himself.

"It's one of his closest representatives," Tygart told CBS' Scott Pelley, according to a news release from the network that included excerpts of the interview. "I've told the federal government in its investigation on the civil fraud side, so I don't think it would be appropriate now to name the name because it's still one of his closest representatives."

Some other points of dispute:

--Armstrong told Winfrey he only used the banned blood booster EPO in small amounts. USADA says that's not true, either.

"He used a lot of EPO," Tygart said. "You look at the '99 Tour de France samples, and they were flaming positive, the highest that we've ever seen. And he's now acknowledged those were positive."

--Armstrong told Winfrey he did not push his teammates to dope, contrary to USADA's evidence, which included sworn statements from teammates.

"He was the boss," Tygart told Pelley. "The evidence is clear he was one of the ringleaders of this conspiracy that pulled off this grand heist that defrauded using tens of millions of taxpayer dollars, defrauded millions of sports fans and his fellow competitors."

--In his interview with Winfrey, Armstrong said he looked up the word "cheater" in the dictionary and said he didn't think it applied to himself.

"It's amazing," Tygart told Pelley. "You could go to almost any kindergarten in this country or frankly around the world and find kids playing tag or four square and ask them what cheating is. Every one of them will tell you it's breaking the rules of the game. No real athlete has to look up the definition of cheating. And it's offensive to clean athletes who are out there working hard to play by the rules that apply to their sport."